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Step 2 - What Type of IC do you Have?


Categorizing IC as connected or disconnected is not as straightforward as it initially seems. For example, is a roof that drains to a lawn, that drains to a bioretention with an overflow drain disconnected from the stormwater system? Most storms will likely infiltrate into the ground with a system like this, but there are many factors including sizing of the system, soil porosity, turf compaction, and storm size that influence what infiltrates on site and what runs off. Observation during storm events can help to determine how effective these systems are at capturing and retaining runoff.

videoIconVenture into the world of IC with Dr. Mike Dietz


drainage Image drainage Image 2
An important distinction when dealing with impervious cover is whether it is connected or disconnected. (Left image) A parking lot which is directly connected to the drainage system, which flows into a nearby stream. (right image) Runoff from the impervious rooftop is channeled via the leader into an extensive lawn area where the water can infiltrate, effectively disconnecting this portion of the roof from the drainage system.